To explore the differences in the status of co-morbid combinations and health-related quality of life between urban and rural middle-aged and elderly people, and to provide a reference for improving the health of middle-aged and elderly people with co-morbid combinations of chronic diseases.

A total of 6 481 middle-aged and elderly people aged ≥50 years with at least two chronic diseases in China Healthy Aging and Reproductive Lifestyle Survey (CHARLS) 2020 were selected. The basic characteristics of urban and rural chronic disease co-morbid middle-aged and elderly people were described, the health-related quality of life was evaluated using the health utility value of EQ-5D-3L, and the combination of urban and rural chronic disease co-morbid combinations was analyzed using the association network diagram and Apriori association rule.

The health utility value of the elderly in urban chronic disease co-morbidities was 0.8532±0.2400, which was higher than that of the elderly in rural chronic disease co-morbidities (0.8409±0.1952). The top five urban strong link chronic disease co-morbidity combination weights were: hypertension+dyslipidemia; hypertension+heart disease; hypertension+arthritis; gastric disease+arthritis; dyslipidemia+heart disease. In rural areas, there were: gastric disease+arthritis; hypertension+arthritis; hypertension+dyslipidemia; and hypertension+gastric disease. Chronic disease co-morbidities in rural middle-aged and elderly people produced 105 association rules and 86 association rules in urban. Among the top 10 association rules in terms of strength of association rules, there were 9 association rules for hypertension and 1 association rule for chronic lung disease in the rural posterior, while there were 6 association rules for hypertension, 3 association rules for dyslipidemia and 1 association rule for chronic lung disease in the urban posterior.

Health related quality of life of elderly people with chronic disease co-morbidities was higher in urban than in rural areas, with emphasis on pain management and depression and anxiety management in elderly people with chronic disease co-morbidities. There are differences in the combination of chronic disease co-morbidities in urban and rural areas, and the binary, ternary, and quaternary co-morbidity associations between common chronic disease illnesses are high, and hypertension and other chronic diseases and co-morbidities are the highest, and attention should be paid to preventive treatment of hypertension.